Note: The following commentary has been slightly adapted from an op-ed
published in the Viewpoints section of the Houston Chronicle of 13 Nov. 2004.
See:http://www.chron.com/cs/CDA/ssistory.mpl/editorial/outlook/2899959

Houston finally has rail transit. Trains carry 30,000 passenger-trips a day on the Main Street line. The Metropolitan Transit
Authority's applications for federal money to build extensions are
in. So why are Metro's new leaders rethinking rail once again?

For three days in late October, Metro board members, a panel of
experts, elected officials, and community representatives listened
as rail suppliers presented a dozen different rail technologies. The
purpose of the forum was to verify that decisions approved by the
previous Metro board and Houston voters last November really
are the best we can do to take Houston into the 22nd century. In
other words, have we chosen a technology that will offer the
greatest service safety, accessibility, frequency, and speed for the
cost?

Light rail transit (LRT) is the most popular rail transit technology in the United
States, with over 20 systems in operation, and another three under
construction. On Nov. 2, voters in Phoenix and Denver approved
light rail expansion. A light rail line at ground level is less than half
as expensive as any other urban rail transit option. That's critical:
the Federal Transit Administration (FTA) awards funding based on
cost effectiveness; a more expensive system is only justified if it
attracts significantly more passengers.

The leading argument against light rail is the number of crashes
between autos and rail on the Main Street line. But most of the
light rail accidents have been minor fender-benders like those that
happen daily on Houston freeways. ironically, figures reported by
transportation reporter Lucas Wall in the Chronicle suggest that
the light rail has actually reduced the number of accidents on the
line. Metro's studies for light rail extensions include design
features like signalized left turn lanes that will make future lines
safer than Main Street.

Light rail transit offers flexibility. Ground-level light rail doesn't necessarily require tracks in streets. Most light rail systems
use long stretches of abandoned railroad corridors, crossing streets but not running
in them. In difficult or congested areas, light rail can also run elevated or in subway
without driving up the cost of the rest of the system. [Photo of Houston LRT on Main St.: L. Henry]

By contrast, alternate technologies like people movers, mini-metros, and monorails require the entire route to be separated,
either by elevating it, putting it underground, or fencing it off.
That's costly. The question is whether the benefits warrant the expense.

Total separation allows for automated, driverless operation, but
the benefits of this are often not as dramatic as touted. The labor
costs saved by eliminating drivers may be offset by higher
maintenance expense, and the closely spaced trains promised by
automation don't always materialize. For example, the fully
computerized BART system in San Francisco can barely operate
a train every two minutes; meanwhile, Toronto runs streetcars in
the same lanes as automobiles just as frequently. That's a lot of
capacity; two-car light rail trains running every three minutes – the
design capacity of the Main Street line – can carry 8,000 people
an hour in each direction.

Higher top speeds offered by grade separation (be it with light rail
or another technology) also have limited benefits in practice. Only
about half the travel time on the Main Street line consists of travel;
the rest is spent in stations. Thus, doubling the top speed on Main
Street would only reduce the travel time by a quarter. On the
planned North Hardy route, passing tracks at stations will allow
future express trains to skip some stations, offering greatly
reduced travel time without much additional cost. In any case,
riders seem to care more about predictable travel times than
overall speed.

Transit planners across the United States have concluded that the
benefits of extensive grade separation are not worth the cost
except in very dense cities like New York. Elsewhere, surface light
rail delivers comparable benefits at a fraction of the cost. Light rail
can also bring benefits that other technologies cannot.

As the new restaurants and lofts along and near the Main Street
line show, light rail can not only blend into a neighborhood but
actually improve it. The same cannot be said for an elevated train.
Elevated guideways look sleek in computer renderings, but are
less elegant, with thickened columns, electric conduits and
emergency walkways. But it is the stations that are the real
problems: imagine a building, 50 feet wide and 200 feet long,
suspended over a city street, with four escalators and two
elevators to the sidewalks below. That is obtrusive in downtown,
let alone in a residential neighborhood.

The reality is that elevated transit systems are best placed in
existing corridors like rail lines or freeways. That is fine when
those corridors are where the people are; but that's not generally
the case. On Fulton, the alternative to street-running rail serving
the neighborhood would be an elevated line in the middle of the
Hardy Toll Road. That would serve mainly industrial areas while
bypassing neighborhoods and destinations like Northline Mall
entirely.

There are corridors in Houston – like Westpark – that might be
well suited for elevated lines. But that can be done with light rail;
using a different technology there would require either a second
north-south line through downtown – duplicating the investment
we have already made at higher cost – or make riders transfer to
light rail or bus to get downtown. Sticking with a single technology
will result in a more convenient, more flexible system. It will also
reduce maintenance costs.

Ultimately, Metro isn't facing a technology problem at all.
Passengers don't care about automation or magnetic levitation or
grade separation. They care whether the ride is comfortable and
reasonably fast, how long they wait and whether they have to
transfer and, most importantly, if they can get where they want to
go. Metro's mission is to meet those needs at the lowest cost, not
to reinvent the wheel.